[PD] multiple devices help

[Frank Barknecht]

Hi,
Josh Steiner hat gesagt: // Josh Steiner wrote:
> So my quesion is this:  how do send audio to different sound devices from
> pd?  I see in the "Test Audio and Midi" patch that you can send audio to
> different channels with [dac~ 2] or [dac~ 3] , so is this all i need to do
> in order to get it to work?  

This, and you have to start pd with a list of the soundout devices you
want to use like

$ pd -soundoutdev 0,1

starting from 0 as usual.

> i did some archive searching and came up with this:
> 
> from IOhannes m zmoelnig about "pd-patch for (better) multidevice support"
> 
> http://iem.kug.ac.at/mailinglists/pd-list/2001-11/0316.html

This is already included in PD 0.35 since at least test17. 

I see another problem with your setup, and that is the hardware side.
If you use several consumer soundcards without synchronization instead
of a decent multichannel card, it might or probably will happen, that
your audio will run out of sync. This means: the samples you send
synchronized from the PD DSP-chain will come out of the four
soundcards at different times, because each of the soundcards has a
different understanding of absolute time because of slight differences
in their clock chips.

Depending on the things you do, this might be nasty, *especially* if
your installation is running for a long time, because your audio data
will differ more the longer it can run out of sync. Maybe stopping
audio in PD from time to time could help.

ciao,
-- 
 Frank Barknecht                               _ ______footils.org__